The invention relates to anticlumping products as well as to their mixtures with other products, notably other anticlumping agents and more particularly fatty acids such as stearic acid. It also relates to a treatment for preventing the dumping or the setting up or setting solid of salts, simple fertilizers and complex fertilizers.
It is known that salts, simple and complex fertilizers exhibit a high tendency to clump-formation, that is to say setting up or setting solid, notably when they are subjected to considerable pressure and climatic variations, namely during storage prior to their utilization. It is emphasized that such clumping can be manifested, for example, by the conversion of a sack of fertilizer into a single lump which is absolutely unusable. In the case of storage in a silo, the setting up may be such that the crust formed must be broken by means of hammer picks, breakers, etc.
Among the salts and simple fertilizers the invention relates to, one may cite nitrogenous salts such as ammonium, or potassium, nitrates, ammonium and calcium nitrates, mono-ammonium and diammonium sulfates, urea and potassium chloride; as regards complex fertilizers, it is recalled that they are constituted by complex mixtures of salts based on at least two of the elements of the group constituted by nitrogen, phosphorus and potassium, these fertilizers being identified by formulae of the NPK.sub.x-y-z type in which x, y, z respectively denote the percentage of nitrogen, of phosphoric anhydride and of K.sub.2 O of the mixture constituting the complex fertilizer.
Applicants have unexpectedly found that, the non-hydrosoluble amine salts, notably alkanolamine, of alkylarylsulfonic acids are endowed with remarkable anticlumping properties with respect to salts, simple fertilizers and complex fertilizers. In the following of the description the term "aryl" in the phrase alkylarylsulfonic, designates the naphtalene ring, this being or not substituted.
The anticlumping product for salts, simple fertilizers and complex fertilizers, according to the invention comprises as active substance at least one non-hydrosoluble salt of an amine, notably of an alkylamine, cycloalkylamine or aromatic amine, including from 2 to 22 carbon atoms, and preferably of an alkanolamine having preferably from 2 to 12 carbon atoms, with an alkylarylsulfonic acid whose alkylaryl radical includes from 11 to 32 carbon atoms.
By the expression alkylaryl-sulfonic acid, is denoted all possible mixtures of acids the aromatic part of which may be mono- or polyalkyl substituted, including, for a given degree of substitution--that is to say a given number of alkyl substituents on the aromatic part--, all possible positions of the substituents respectively with one another, and for a given position, all the possible optical and geometric isomers.
The degree of substitution indicated in the formula by one of the suffixes of the group "mono-, di-, tri-, tetra-, penta-" (monoalkylaryl-sulfonic, di-alkylaryl-sulfonic, trialkylaryl-sulfonic, tetraalkylaryl-sulfonic, pentaalkylaryl-sulfonic acids) is an average degree of substitution signifying that the molar ratio alcohol/aryl used for the synthesis of the alkylaryl compound is 1/1, 2/1, 3/1, 4/1, 5/1, and leading in fact, for each degree of substitution, to complex mixtures of mono-, di-, tri-, tetra-, and pentaalkylaryl-sulfonic acids.
In the same way, the term sulfonic is such that it must be understood, for a given alkylaryl radical, as all possible mixtures of alkylaryl-mono-, -di- or -trisulfonic acids, including all their optical and geometric isomers.
The anticlumping treatment according to the invention is characterised by the fact that the salt, simple fertilizer or complex fertilizer is treated with an amount of 0.005 to 0.2% by weight with respect to the salt, simple or complex fertilizer of the anticlumping product according to the invention, having if necessary also recourse to an inert filler applied in the proportion of at the most about 4% by weight with respect to the salt, simple or complex fertilizer.
Other characteristics of the invention will appear in the description and the examples which follow and by means of which the invention will be well understood.
To fight against the setting up of salts, simple or complex fertilizers, recourse is therefore had to a product comprising at least one salt of an amine, notably of an alkylamine, cycloalkylamine, or an aromatic amine, including 2 to 22 carbon atoms, and preferably of an alkanolamine, having preferably from 2 to 12 carbon atoms, with an alkylaryl-sulfonic acid whose alkylaryl radical includes from 11 to 32 carbon atoms.
As regards firstly the alkylamine, the cycloalkylamine or the aromatic amine, it is advantageously selected from the group comprising the following amines:
triethylamine, PA1 dipropylamine, PA1 diisopropylamine, PA1 tripropylamine, PA1 dibutylamine, PA1 diisobutylamine, PA1 piperidine, PA1 cyclohexylamine, PA1 pyridine, PA1 aniline, PA1 morpholine, PA1 quinoleine, PA1 pyrrole, PA1 imidazole, PA1 monoethanolamine, PA1 diethanolamine, PA1 triethanolamine, PA1 .beta.-propanolamine, PA1 .beta.-dipropanolamine, PA1 .beta.-tripropanolamine, PA1 monoisopropanolamine, PA1 diisopropanolamine, PA1 triisopropanolamine, PA1 monoisobutanolamine, PA1 diisobutanolamine, PA1 triisobutanolamine, PA1 tripropyl and triisoprophlnaphtalene-sulfonic, PA1 tripropyl and triisopropylmethylnaphtalene-sulfonic, PA1 tripropyl and triisopropyldimethylnaphtalene-sulfonic, PA1 diamyl naphtalene-sulfonic, PA1 diamyl methylnaphtalene-sulfonic, PA1 diamyl dimethylnaphtalene-sulfonic, PA1 (by "amyl" is designated linear amyl, isoamyl and tert-amyl). PA1 dibutyl and diisobutylnaphtalene-sulfonic, PA1 dibutyl and diisobutylmethylnaphtalene-sulfonic, PA1 tributyl and triisobutylnaphtalene-sulfonic, PA1 tributyl and triisobutylmethylnaphtalene-sulfonic PA1 dibutyl and diisobutyldimethylnaphtalene-sulfonic, PA1 tetrapropyl and tetraisopropbylnaphtalene-sulfonic, PA1 tetrapropyl and tetraisopropylmethylnaphtalene-sulfonic, PA1 dihexyl naphtalene-sulfonic, PA1 dihexyl methylnaphtalene-sulfonic. PA1 tributyl and triisobutyl naphtalene-sulfonic PA1 tributyl and triisobutyl methylnaphtalene-sulfonic, PA1 tetrapropyl and tetraisopropylnaphtalene-sulfonic, PA1 tetrapropyl and tetraisopropylmethylnaphtalene-sulfonic. PA1 tributyl and triisobutyldimethylnaphtalene-sulfonic, PA1 dihexyldimethylnaphtalene-sulfonic, PA1 tetrapropyl and tetraisoprophldimethylnaphtalene-sulfonic, PA1 tetrabutyl and tetraisobutylnaphtalene-sulfonic, PA1 tetrabutyl and tetraisobutylmethylnaphtalene-sulfonic, PA1 tetrabutyl and tetraisobutyldimethylnaphtalene-sulfonic, PA1 pentapropyl and pentaisopropylnaphtalene-sulfonic, PA1 pentapropyl and pentaisopropylmethylnaphtalene-sulfonic, PA1 pentapropyl and pentaisopropyldimethylnaphtalene sulfonic, PA1 pentabutyl and pentaisobutylnaphtalene-sulfonic, PA1 pentabutyl and pentaisobutylmethylnaphtalene-sulfonic, PA1 pentabutyl and pentaisobutyldimethyl naphtalene-sulfonic, PA1 triamylnaphtalene-sulfonic, PA1 triamylmethylnaphtalene-sulfonic, PA1 triamyldimethylnaphtalene-sulfonic, PA1 ethyl-2-hexyl naphtalene-sulfonic, PA1 ethyl-2-hexyl methylnaphtalene-sulfonic, PA1 ethyl-2-hexyl dimethylnaphtalene-sulfonic, PA1 tetraamylnaphtalene-sulfonic, PA1 tetraamylmethylnaphtalene-sulfonic, PA1 tetraamyldimethylnaphtalene-sulfonic, PA1 dinonylnaphtalene-sulfonic, PA1 dinonylmethylnaphtalene-sulfonic, PA1 dinonyldimethylnaphtalene-sulfonic. PA1 tributyl and triisobutyl dimethylnaphtalene-sulfonic PA1 tetrapropyl and tetraisorpopyldimethylnaphtalene-sulfonic, PA1 pentapropyl and pentaisorpopylnaphtalene-sulfonic, PA1 pentapropyl and pentaisopropylmethylnaphtalene-sulfonic, PA1 pentapropyl and pentaisopropyldimethylnaphtalene-sulfonic, PA1 tetrabutyl and tetraisobutylnaphtalene-sulfonic, PA1 tetrabutyl and tetraisobutylmethylnaphtalene-sulfonic, PA1 tetrabutyl and tetraisobutyldimethylnaphtalene-sulfonic, PA1 pentabutyl and pentaisobutylnaphtalene-sulfonic, PA1 pentabutyl and pentaisobutylmethylnaphtalene-sulfonic, PA1 pentabutyl and pentaisobutyldimethylnaphtalene-sulfonic.
or a mixture of at least two of these compounds.
As regards the alkanolamine, the latter may be a monosubstituted, disubstituted or trisubstituted amine, advantageously selected from the group comprising:
or a mixture of at least two of these compounds.
Among the group which has just been mentioned, are preferred monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, or a mixture of at least two of these compounds.
As regards the alkylarylsulfonic acid considered, it is constituted by an alkylnaphtalenesulfonic acid having from 11 to 32 carbon atoms.
According to a first embodiment, the invention relates to the alkylnaphtalene-sulfonic acid comprising from 11 to 23 carbon atoms.
According to a second embodiment, the invention relates to the alkylnaphtalene-sulfonic acids comprising from 24 to 32 carbon atoms.
In the case of the alkylnaphtalene-sulfonic acids, comprising from 11 to 23 carbon atoms, those comprising from 18 to 23 carbon atoms are preferred.
In the case of alkylnaphtalene-sulfonic acids comprising from 24 to 32 carbon atoms, those comprising from 24 to 28 carbon atoms are preferred.
The alkylaryl-sulfonic acid (being understood that sulfonic means a -mono-, -di-, or -trisulfonic) is advantageously selected in the group comprising the acids having from 11 to 23 carbon atoms and which are:
Among the above-mentioned alkylarlyl-sulfonic acids, the most preferred acids are the eight following acids (these acid groups will be designated under group A)
The alkylaryl-sulfonic acid can also advantageously be chosen in the group comprising the following acids having from 24 to 32 carbon atoms:
Among the alkylaryl-sulfonic acids above-mentioned, the twenty-two following acids are most particularly preferred (this acid group will be designated by group B)
A preferred class of anticlumping products for salts, simple and complex fertilizers, according to the invention comprises as active substance at least one non-hydrosoluble salt selected in the group constituted by the sulfonates of monoethanolamine on the one hand and of monoisopropanolamine on the other hand of the eight acids of group A and of the twenty two acids of group B.
The invention also relates to the mixture of at least two of the salts obtained from the above-mentioned amines and alkylaryl-sulfonic acis.
As regards the amine alkylaryl sulfonates, these products as well as their preparation are well-known and described in the scientific litterature as surface-active products.
As regards the amine alkylarylsulfonates whose corresponding sulfonic acid has a number of carbon atoms from 11 to 17, they are non-hydrosoluble insofar as the amine being part of the composition of the above-mentioned salt be heavy enough, that is to say comprises at least 7 carbon atoms.
As regards the amine alkylarylsulfonates, whose corresponding sulfonic acids comprise a number of carbon atoms from 18 to 23, they are non-hydrosoluble, whatever the amine considered and being part of the composition of the above-mentioned salt.
It is the same for amine alkylarylsulfonates whose corresponding sulfonic acid comprises from 24 to 32 carbon atoms.
The non-hydrosoluble alkylarylsulfonates being part of the composition of the anticlumping products according to the invention are soluble in organic solvents and can be processed in industrial solvents such as products derivated from petroleum, notably from fuel, oils, notably aromatic and naphtenic oils etc. or molten. When treating the salt, the simple fertilizer or the complex fertilizer, in order to prevent it from clumping and setting up, the non-hydrosoluble alkylarylsulfonates can be processed with a coating agent selected in the group constituted by chalk, infusory earth talk, clays and the like.
The fact that one can resort or not to such a coating agent depends on the quality of the salt, of a simple fertilizer or complex fertilizer to be treated.
In order to treat a salt, a simple or complex fertilizer in order to prevent it from setting up, according to the invention, the quantity is 0.005 to 0.2% by weight with respect to the above-mentioned salt, simple or complex fertilizer of the anticlumping product according to the invention, is supplied.
The incorporation can take place:
by spraying onto the salt, simple or complex fertilizer to be treated either the molten product, or a solution in a solvent of the anticlumping product, this spraying being possibly followed by a coating by a filler such als chalk, infusory earth, talc, clays and the like;
by coating the salts, simple or complex fertilizers by means of a filler of the above-mentioned type, followed either by spraying of the above-said solution of the anticlumping product, or by spraying of the latter in the molten state;
by absorption of the anticlumping product according to the invention on a filler of the above-mentioned type and then coating of the salts, simple or complex fertilizers by the thus treated filler;
by mixing the anticlumping product with solutions of salts, simple or complex fertilizers to be treated during the manufacture of the latter before the production of the dry product.
by introducing the anticlumping product according to the invention, in the shape of power or flakes, on to the salt, simple or complex fertilizer to be treated, immediately after their shaping into granules or prills and before coating, the salt, simple or complex fertilizer having to be hot enough as to cause the melting and the uniform distribution of the anticlumping product.
The amounts of the anticlumping product applied may vary from 0.005 to 0.2% by weight with respect to the salt, to the simple fertilizer and to the complex fertilizer; preferably these amounts are comprised between 0.02 and 0.1%.
The amount of coating fillers possibly applied may also range up to 4% with respect to the salt or fertilizer treated: in general amounts of about 0.2 to 1% are sufficient.
The invention also relates to the mixtures of at least one of the anticlumping products according to the invention with other products, notably other anticlumping agents and more particularly fatty acids including notably from 4 to 22 carbon atoms. As regards these aliphatic or aromatic fatty acids, it is preferable to select those from the group comprising: butyric, hexanoic, ethylhexanoic, capric, undecylic, lauric, palmitic, stearic, oleinic, linoleic, linolenic, ricinoleic, benzoic, benzenepolycarboxylic, naphthoic, naphthalenepolycarboxylic acid.
In the above-indicated group of fatty acids, stearic acid is preferred.
The fatty acids which can be part of the composition of the mixture with anticlumping agents according to the invention are present in the above-said mixture in the proportion of about 30% to about 70% by weight, calculated with respect to the total weight of the mixture.
In particular, for mixtures comprising stearic acid, the proportion advantageously preferred of stearic acid is from about 50 to 70% by weight, with respect to the total weight of the mixture, this proportion varying according to the characteristics of the fertilizers and of the salts to be treated, notably according to the process for preparing the fertilizer or the salt, the residual moisture, the surface hardness, etc.
As regards the anticlumping agents which can be part of the composition of the mixture, may be mentioned among the products currently used at the present time the fatty amines marketed for this purpose.
To illustrate the anticlumping properties of the products according to the invention, a certain number of tests were carried out consisting of forming cylindrical specimens of 4 cm height and 4 cm diameter using the treated or untreated salt or fertilizer, and subjecting them to a pressure of 0.8 kg/cm.sup.2 for 48 hours or more, in an enclosure where the temperature and humidity can possibly be modified in two cycles for example of 24 hours comprising a hot and moist period during the day (about 29.degree. C. and about 60% relative humidity) and a cold and dry period during the night (about 26.degree. C. and 40% relative humidity).
The specimens were then crushed between two parallel plates of a dynamometer.
The crushing force observed constitutes a measure of the degree of setting up of the salt or of the fertilizer. The value 100 is given to the crushing strength observed for a treatment taken as reference, and the values found are expressed for the other treatment as a percentage with respect to the reference measurement. The lower this value, the better the anticlumping treatment.
For each treatment, 10 specimens were formed and the average percentage of the degree of setting up indicated.
To evaluate the anticlumping properties of the product according to the invention, actual stackings were also carried out. For this, 4 to 6 bags of fertilizers treated with products according to the invention were arranged on a paddle, then above the latter was arranged a paddle inverted and the whole was loaded with weights which could reach from 4 to 10 tons.
After 1 to 3 months of storage under load, the percentage of setting up was evaluated by weighing the lumps. The result of the clumping is expressed in % of clumping with respect to an effectiveness control by forming the ratio of the weight of clumps of the products according to the invention to the weight of clumps of the control. The hardness of these clumps or their ability to be crumbled is also taken as a criterion.
To evaluate the dust on taking up again the fertilizers treated according to the invention, the latter were subjected to a fall from a given height and the amount of dust formed estimated by weighing, or indeed again the latter is evaluated by opacity measurements, the test being carried out in a closed container with a transparent wall.
The dust values obtained were divided for each of the treated fertilizers by the value obtained by the fertilizer taken as a control and thus a dust index was obtained. The lower the index, the better the anti-dust processing effected.
For the preparation of the acids from which the above-mentioned products according to the invention are prepared, the following process can be applied:
Naphtalene, methyl-naphtalene or dimethyl naphtalene or any other petroleum distillation cut, essentially constituted by at least one of the above-mentioned aromatic compounds, is mixed in order to be alkylated to the appropriate alcohol in the desired ratio. The mixture is brought to a temperature comprised between 40.degree. and 80.degree. C. to be selected according to the volatility and reactivity of the used alcohol, and concentrated sulfuric acid (66.degree. B) is introduced in an amount sufficient to provide alkylation. This one occurs by deshydratation between the alcohol and the aromatic ring. The mixture is allowed to react at the temperature to which it has been brought for a duration comprised between 2 and 5 hours.
Then an excess of concentrated acid or oleum of about 20% of SO.sub.3 is added in a ratio comprised between 2 and 6 moles of acid per mole of aromatic compounds, the quantity being function of the substitution of the abovesaid aromatic compound. The temperature is maintained at the value comprised between 40.degree. and 80.degree. for a duration of 2 to 5 hours.
Then an hydration reaction is carried out under important cooling down, at a temperature under 80.degree. C. and the sulfuric acid is allowed to settle. The alkylarylsulfonic acid is obtained in the superior phase.
The alkylarylsulfonic acid is then transformed into alkylaryl sulfonate of amine by means of neutralization in hot conditions at a temperature comprised between 40.degree. C. and 70.degree. C., with the appropriate amine. Thus, in the case of the synthesis of a monoethanolamine salt, the alkylarylsulfonic acid will be neutralized by monoethanolamine and in the case of the synthesis of isopropanolamine salt, the neutralization is carried out by isopropanolamine.
Tetraisopropylmethylnaphthalene-monosulfonic acid may be prepared by treating 1 mole of methylnaphthalene with 4 moles of isopropanol in the presence of an excess of sulfuric acid, then by sulfonating with, for example, oleum with 20% of SO.sub.3 ;
tetraisopropyldimethylnaphthalene-monosulfonic acid may be prepared by treating 1 mole of dimethylnaphthalene with 4 moles of isopropanol in the presence of an excess of sulfuric acid and then by sulfonating with, for example, oleum with 20% of SO.sub.3.